The standardization of a technology of providing stereoscopic contents has been in progress. Such standardization induces the related technologies to be rapidly advanced based on various digital image devices such as a digital television (TV), a mobile phone, a digital camera, a digital versatile disk (DVD), and a portable multimedia player (PMP). The stereoscopic contents provide natural images with superior three-dimensional (3D) effect and excellent reality. Accordingly, technologies for capturing, generating, and displaying the stereoscopic contents have been developed, and relevant technologies for application services and devices using the stereoscopic contents have been also advanced as well.
As a related art, a side-by-side method was introduced for forming a stereoscopic image. The side-by-side method provides a stereoscopic service by reducing left and right images of stereoscopic contents by half and including the reduced left and right images in one frame.
For example, the left image is reduced by half by collecting only odd number vertical lines in the left image, and the right image is reduced by half by collecting only even number vertical lines in the right image, and the reduced left and right images are include in one frame. Since both of the left and right images are included in one frame, it is easy to synchronize the left image with the right image. However, the side-by-side method has disadvantages as well. That is, the image resolution is deteriorated and it is not comparable with typical digital broadcasting.
A frame sequential method was introduced as another method for forming a stereoscopic image according to the related art. The frame sequential method according to the related art encodes a right image and a left image of stereoscopic contents alternatively. The frame sequential method according to the related art advantageously provides a stereoscopic image having a full resolution that is identical to an original image.
However, the frame sequential method may disadvantageously cause a difficulty of synchronizing a left image with a right image and may provide a related service with one of the right and left images ignored if one of the right and left images is broken. Therefore, the frame sequential method according to the related art is not comparable with typical digital broadcasting.
Furthermore, an encoding method according the related art was introduced for providing stereoscopic contents while sustaining comparability with typical digital broadcasting. This encoding method encodes left and right images using different CODECs such as MPEG-2(Moving Picture Expert Group-2) and Advanced Video Coding (AVC).
Moreover, another encoding method was introduced for providing stereoscopic image with the comparability sustained. This encoding method encodes left and right images using relation between the left and right images.
Although these methods sustain the comparability with the typical digital broadcasting system, these methods require additional CODECs for individually coding and decoding the left and right images, thereby having high system complexity. Also, it is difficult to apply these methods to HD level high resolution digital broadcasting services due to limitation of a digital broadcasting bandwidth.